The present invention relates to the art of document and financial transaction security. It finds particular application in conjunction with the prevention and detection of counterfeiting and alteration of charge or credit cards. It is to be appreciated that the invention has broader applications including identification cards, banking and money transfer cards, passports, key cards and other documents and structures which are to be monitored and protected against alteration and forgery.
Substantial amounts of goods and monies are stolen each year through fraudulent credit card transactions. the fraudulent credit card transactions are aided not only by the thief who steals credit cards, but also by dishonest merchants, dishonest bank employees with access to credit card account information, counterfeiters, credit card alterers, forgers, and the like.
Various techniques have been suggested to stop or reduce credit card fraud. However, an effective technique which operates within the physical parameters of conventional credit cards has proven elusive. One suggested technique was to provide an electromagnetic recording of account information on the card. Another technique was to embody a structure within the plastic of the card which rendered it difficult to alter or reproduce. For example, it has been suggested that thin threads be embedded in the plastic, holographic images be imprinted on the plastic, and the like. In another technique, the carholder was assigned a personal identification number which was compared with a personal identification number stored at the bank or credit card headquarters to verify that the true card owner was undertaking the transaction.
Each of these techniques have had its drawbacks. Electromagnetically coded information has been found to be partially erased or otherwise rendered unreliably readable in a significant percentage of legitimate credit cards. Placing alledgely unalterable structures in the plastic of the card has required counterfeiters and alterers to improve their skills but has stopped neither counterfeiting nor altering. Moreover, such techniques have tended to be expensive. Personal identification numbers have been stolen by dishonest bank employees and remembered by merchants, who also retain the other account information on the sales receipt. Further, merchant verification of every credit card transaction has been considered by many to be too time consuming to be acceptable.
The present invention provides an improved credit card and verification technique which overcores the above-referenced problems and others.